/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: LoadDocument.java,v 1.2.4.1 2005/09/06 07:14:12 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.dom;

import com.sun.org.apache.xalan.internal.XalanConstants;
import java.io.FileNotFoundException;

import javax.xml.transform.stream.StreamSource;

import com.sun.org.apache.xalan.internal.xsltc.DOM;
import com.sun.org.apache.xalan.internal.xsltc.DOMCache;
import com.sun.org.apache.xalan.internal.xsltc.DOMEnhancedForDTM;
import com.sun.org.apache.xalan.internal.xsltc.TransletException;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.utils.SecuritySupport;
import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.dtm.DTMManager;
import com.sun.org.apache.xml.internal.dtm.ref.DTMDefaultBase;
import com.sun.org.apache.xml.internal.dtm.ref.EmptyIterator;
import com.sun.org.apache.xml.internal.utils.SystemIDResolver;

import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;

/**
 * @author Morten Jorgensen
 */
public final class LoadDocument {

  private static final String NAMESPACE_FEATURE =
      "http://xml.org/sax/features/namespaces";

  /**
   * Interprets the arguments passed from the document() function (see
   * com/sun/org/apache/xalan/internal/xsltc/compiler/DocumentCall.java) and returns an
   * iterator containing the requested nodes. Builds a union-iterator if
   * several documents are requested.
   * 2 arguments arg1 and arg2.  document(Obj, node-set) call
   */
  public static DTMAxisIterator documentF(Object arg1, DTMAxisIterator arg2,
      String xslURI, AbstractTranslet translet, DOM dom)
      throws TransletException {
    String baseURI = null;
    final int arg2FirstNode = arg2.next();
    if (arg2FirstNode == DTMAxisIterator.END) {
      //  the second argument node-set is empty
      return EmptyIterator.getInstance();
    } else {
      //System.err.println("arg2FirstNode name: "
      //                   + dom.getNodeName(arg2FirstNode )+"["
      //                   +Integer.toHexString(arg2FirstNode )+"]");
      baseURI = dom.getDocumentURI(arg2FirstNode);
      if (!SystemIDResolver.isAbsoluteURI(baseURI)) {
        baseURI = SystemIDResolver.getAbsoluteURIFromRelative(baseURI);
      }
    }

    try {
      if (arg1 instanceof String) {
        if (((String) arg1).length() == 0) {
          return document(xslURI, "", translet, dom);
        } else {
          return document((String) arg1, baseURI, translet, dom);
        }
      } else if (arg1 instanceof DTMAxisIterator) {
        return document((DTMAxisIterator) arg1, baseURI, translet, dom);
      } else {
        final String err = "document(" + arg1.toString() + ")";
        throw new IllegalArgumentException(err);
      }
    } catch (Exception e) {
      throw new TransletException(e);
    }
  }

  /**
   * Interprets the arguments passed from the document() function (see
   * com/sun/org/apache/xalan/internal/xsltc/compiler/DocumentCall.java) and returns an
   * iterator containing the requested nodes. Builds a union-iterator if
   * several documents are requested.
   * 1 arguments arg.  document(Obj) call
   */
  public static DTMAxisIterator documentF(Object arg, String xslURI,
      AbstractTranslet translet, DOM dom)
      throws TransletException {
    try {
      if (arg instanceof String) {
        if (xslURI == null) {
          xslURI = "";
        }

        String baseURI = xslURI;
        if (!SystemIDResolver.isAbsoluteURI(xslURI)) {
          baseURI = SystemIDResolver.getAbsoluteURIFromRelative(xslURI);
        }

        String href = (String) arg;
        if (href.length() == 0) {
          href = "";
          // %OPT% Optimization to cache the stylesheet DOM.
          // The stylesheet DOM is built once and cached
          // in the Templates object.
          TemplatesImpl templates = (TemplatesImpl) translet.getTemplates();
          DOM sdom = null;
          if (templates != null) {
            sdom = templates.getStylesheetDOM();
          }

          // If the cached dom exists, we need to migrate it
          // to the new DTMManager and create a DTMAxisIterator
          // for the document.
          if (sdom != null) {
            return document(sdom, translet, dom);
          } else {
            return document(href, baseURI, translet, dom, true);
          }
        } else {
          return document(href, baseURI, translet, dom);
        }
      } else if (arg instanceof DTMAxisIterator) {
        return document((DTMAxisIterator) arg, null, translet, dom);
      } else {
        final String err = "document(" + arg.toString() + ")";
        throw new IllegalArgumentException(err);
      }
    } catch (Exception e) {
      throw new TransletException(e);
    }
  }

  private static DTMAxisIterator document(String uri, String base,
      AbstractTranslet translet, DOM dom)
      throws Exception {
    return document(uri, base, translet, dom, false);
  }

  private static DTMAxisIterator document(String uri, String base,
      AbstractTranslet translet, DOM dom,
      boolean cacheDOM)
      throws Exception {
    try {
      final String originalUri = uri;
      MultiDOM multiplexer = (MultiDOM) dom;

      // Prepend URI base to URI (from context)
      if (base != null && !base.equals("")) {
        uri = SystemIDResolver.getAbsoluteURI(uri, base);
      }

      // Return an empty iterator if the URI is clearly invalid
      // (to prevent some unncessary MalformedURL exceptions).
      if (uri == null || uri.equals("")) {
        return (EmptyIterator.getInstance());
      }

      // Check if this DOM has already been added to the multiplexer
      int mask = multiplexer.getDocumentMask(uri);
      if (mask != -1) {
        DOM newDom = ((DOMAdapter) multiplexer.getDOMAdapter(uri))
            .getDOMImpl();
        if (newDom instanceof DOMEnhancedForDTM) {
          return new SingletonIterator(((DOMEnhancedForDTM) newDom)
              .getDocument(),
              true);
        }
      }

      // Check if we can get the DOM from a DOMCache
      DOMCache cache = translet.getDOMCache();
      DOM newdom;

      mask = multiplexer.nextMask(); // peek

      if (cache != null) {
        newdom = cache.retrieveDocument(base, originalUri, translet);
        if (newdom == null) {
          final Exception e = new FileNotFoundException(originalUri);
          throw new TransletException(e);
        }
      } else {
        String accessError = SecuritySupport
            .checkAccess(uri, translet.getAllowedProtocols(), XalanConstants.ACCESS_EXTERNAL_ALL);
        if (accessError != null) {
          ErrorMsg msg = new ErrorMsg(ErrorMsg.ACCESSING_XSLT_TARGET_ERR,
              SecuritySupport.sanitizePath(uri), accessError);
          throw new Exception(msg.toString());
        }

        // Parse the input document and construct DOM object
        // Trust the DTMManager to pick the right parser and
        // set up the DOM correctly.
        XSLTCDTMManager dtmManager = (XSLTCDTMManager) multiplexer
            .getDTMManager();
        DOMEnhancedForDTM enhancedDOM =
            (DOMEnhancedForDTM) dtmManager.getDTM(new StreamSource(uri),
                false, null, true, false,
                translet.hasIdCall(), cacheDOM);
        newdom = enhancedDOM;

        // Cache the stylesheet DOM in the Templates object
        if (cacheDOM) {
          TemplatesImpl templates = (TemplatesImpl) translet.getTemplates();
          if (templates != null) {
            templates.setStylesheetDOM(enhancedDOM);
          }
        }

        translet.prepassDocument(enhancedDOM);
        enhancedDOM.setDocumentURI(uri);
      }

      // Wrap the DOM object in a DOM adapter and add to multiplexer
      final DOMAdapter domAdapter = translet.makeDOMAdapter(newdom);
      multiplexer.addDOMAdapter(domAdapter);

      // Create index for any key elements
      translet.buildKeys(domAdapter, null, null, newdom.getDocument());

      // Return a singleton iterator containing the root node
      return new SingletonIterator(newdom.getDocument(), true);
    } catch (Exception e) {
      throw e;
    }
  }


  private static DTMAxisIterator document(DTMAxisIterator arg1,
      String baseURI,
      AbstractTranslet translet, DOM dom)
      throws Exception {
    UnionIterator union = new UnionIterator(dom);
    int node = DTM.NULL;

    while ((node = arg1.next()) != DTM.NULL) {
      String uri = dom.getStringValueX(node);
      //document(node-set) if true;  document(node-set,node-set) if false
      if (baseURI == null) {
        baseURI = dom.getDocumentURI(node);
        if (!SystemIDResolver.isAbsoluteURI(baseURI)) {
          baseURI = SystemIDResolver.getAbsoluteURIFromRelative(baseURI);
        }
      }
      union.addIterator(document(uri, baseURI, translet, dom));
    }
    return (union);
  }

  /**
   * Create a DTMAxisIterator for the newdom. This is currently only
   * used to create an iterator for the cached stylesheet DOM.
   *
   * @param newdom the cached stylesheet DOM
   * @param translet the translet
   * @param the main dom (should be a MultiDOM)
   * @return a DTMAxisIterator from the document root
   */
  private static DTMAxisIterator document(DOM newdom,
      AbstractTranslet translet,
      DOM dom)
      throws Exception {
    DTMManager dtmManager = ((MultiDOM) dom).getDTMManager();
    // Need to migrate the cached DTM to the new DTMManager
    if (dtmManager != null && newdom instanceof DTM) {
      ((DTM) newdom).migrateTo(dtmManager);
    }

    translet.prepassDocument(newdom);

    // Wrap the DOM object in a DOM adapter and add to multiplexer
    final DOMAdapter domAdapter = translet.makeDOMAdapter(newdom);
    ((MultiDOM) dom).addDOMAdapter(domAdapter);

    // Create index for any key elements
    translet.buildKeys(domAdapter, null, null,
        newdom.getDocument());

    // Return a singleton iterator containing the root node
    return new SingletonIterator(newdom.getDocument(), true);
  }

}
